EP2428480B1 - Method for operating a textile machine for creating cross-wound spools and textile machine for creating cross-wound spools - Google Patents

Description

The invention relates to a method for operating a cheese-producing textile machine and a cheese-producing textile machine with a plurality of similar jobs, each having a plurality of individual stepper motors designed to drive handling facilities of the job, each stepper motor is associated with a power output stage, by means of which a target value is set for the amount of the current.

Textile machines producing cross-wound bobbins are both winding machines and spinning machines, such as open-end rotor spinning machines. Winding machines wind a yarn from a delivery bobbin onto a cross-wound bobbin. Run-off bobbins may be spin cops originating from ring spinning machines, which are rewound into cheeses. The yarn may also be withdrawn from an open-end spinning device, also referred to as a spinning rotor, and then wound onto a cross-wound bobbin.

The DE 101 39 075 discloses an open-end rotor spinning machine having a plurality of similar work stations, each having an open-end spinning device for producing a thread, a winding device with a coil frame and a Fadenchangiereinrichtung for producing a cross-wound bobbin, a pivotally mounted, unterdruckbeaufschlagbare suction nozzle and means for preparing a re-spinning Have thread end. Furthermore, each workstation has a winding device with a drive drum acted on by a reversible single drive for driving a cross-wound bobbin and a single motor driven Fadenchangiereinrichtung for defined laying of the running on the cross-wound yarn. There is a via a single drive between a thread receiving position in the region of the winding device and a yarn transfer position in the region of a Anspinnorgans pivotable suction nozzle available. Each workstation has a single-motor-driven thread take-off device, and the individual drives can be controlled by a workstation computer.

The DE 101 39 075 thus deviates from the traditional concept of an open-end rotor spinning machine, in which the handling equipment of the jobs are centrally driven and the power is transmitted to the jobs by means of machine-long shafts or belts.

Stepped motors are used as single drives. These are simpler in construction and thus cheaper than three-phase motors and less susceptible to wear than DC motors. Accordingly, the control of the stepper motors is also simple.

The DE 10 2005 020 579 A1 also discloses a cross-wound producing textile machine with workstations, each having individual drives designed as stepper motors for driving handling devices of the workstation. The stepper motors of several workstations are connected to the supply of electrical energy to a common power supply.

Stepper motor controllers are usually offered for three operating states. At standstill windings or phases of the stepping motor are energized with low stand-by current. When accelerating the stepper motor is a current with a very large current amplitude used. If the stepping motor has reached its operating speed, then it is possible to switch to a running operating state in which the current amplitude of the winding currents lies between that at standstill and in the acceleration phase. Due to the simple control, stepper motors are equipped with processors with low computing power.

From the DE 40 03 552 A1 It is known to set the actual value of the current in a stepper motor by a control to a predetermined current setpoint. An easy way to realize a current control in stepper motors, is in the DE 2 258 862 A1 revealed two-step regulation.

In the application of stepper motors in textile-producing textile machines, the definition of further operating states is necessary because, for example, in an open-end rotor spinning machine in normal spinning operation, a different speed and a different moment are required than, for example, during piecing. The Fadenchangiereinrichtung must be able to move in one direction and the other. With approach to the end face of the coil, the speed of the thread guide or the speed of the stepping motor is reduced and the motor finally reversed.

For this reason, stepping motors which drive handling devices of an open-end rotor spinning machine are assigned a fixed movement profile. This profile includes the motor frequencies, that is, the frequency of the impressed current, and the associated amounts of the currents. In the case of a sinusoidal supply, the amount is given by the current amplitude. In the case of a block-shaped feed, the block current is specified. The motor frequency specifies the speed and the amount of current the drive torque. The amount of current is adjusted to the load torque in the respective operating state. The amount of current stored in the profile is given to the power output stage of the stepper motor as the setpoint. This always sets the same setpoint for the same operating state. This is readily possible since the load torque at a workstation changes only with the defined operating conditions and is essentially the same when a specific operating condition returns.

Since the jobs are all built the same, the same profiles are used for the corresponding handling facilities of other jobs.

It should be noted, however, that the drive torque must overcome not only the payload torque, that is, the moment that causes the desired movement of the handling device, but also moments that cause power loss. In particular friction causes friction. However, the friction moments are strongly dependent on the installation of stepper motors and handling equipment. Since the same amount of current and thus the same drive torque are set for all workstations, the current must be designed for the worst case, ie for the largest expected friction torque. This has the consequence that at individual jobs a larger current is impressed than actually required. However, since the friction moments with respect to the total drive torques are small, the function at the individual jobs is not affected.

However, in view of the multiplicity of workstations with a plurality of stepper motors, the power that has to be provided to cover the currents that are actually not required adds up. As a result, not only the energy consumption of the textile machine is driven unnecessarily high, but the other components, in particular the power supplies that provide the stepper motors and possibly other electrical consumers with energy, must be designed for the increased performance. The power supplies convert the voltage of an electrical power supply network into a suitable voltage for supplying the power output stages of the stepper motors.

It is therefore the object of the present invention to improve the power supply of the stepper motors of cheese-producing textile machines as needed.

The object is achieved by the characterizing features of the method claim 1 and the device claim 4. Advantageous developments of the invention are the subject of the dependent claims.

To solve the problem stepper motors of several jobs are fed by a power supply with limited power. Furthermore, a variable speed representing quantity of at least the stepper motors of a handling device of the plurality of jobs is detected, the target value for the amount of current of these stepper motors is adjusted in dependence on the speed fluctuations representing the size and thereby limits the power absorbed by the power supply.

The invention aims to not arbitrarily increase the power of the power supply, but to limit in an intelligent form, the total power consumption of the stepper motors connected to a power supply. If the real friction torque is smaller than that used in determining the set value for the amount of current, undesired acceleration of the stepping motor occurs. However, this acceleration is interrupted upon reaching the next step, since the stepping of the steps is determined by the frequency of the current, not by its amount. Due to the additional torque, the stepper motor is first accelerated and then decelerated again. In this way, there is a speed fluctuation or a temporary deviation from the speed determined by the frequency of the current. If the amount of current is too small, there will be a loss of step and thus also to a speed fluctuation, the stepper motor is first delayed. For this reason, the set value for the magnitude of the current is adjusted as a function of the variable representing the speed fluctuations, namely preferred in the sense of a regulation. However, two further aspects are essential to the present invention. On the one hand, the setpoint values of all stepper motors of a workstation need not be adapted in the manner described. It is usually sufficient if each of the stepper motors of one or two handling devices are adapted to a job. Advantageously, the stepper motors with the highest power consumption are selected. Thus, the greatest effect on the total power consumption of the stepper motors is achieved. On the other hand, it is crucial that several of these stepper motors, possibly together with other stepper motors or electrical loads, are powered by a power supply. Only then does the power supply not have to be designed for the worst case due to the statistical distribution of the actual friction moments, and the power consumed by the power supply or delivered by the power supply is actually limited.

The limitation of the power is achieved by reducing the power consumption of the respective stepper motors. The adaptation of the current setpoint values described above reduces the power loss of the stepper motors, since the unnecessary deceleration and acceleration of the stepper motors is avoided. The reduction of the power loss has the additional positive effect that the heating of the stepper motors and thus of the work stations is reduced. Too high a temperature can negatively affect the manufacturing process of the textile machine.

To detect the speed fluctuations, the respective stepping motors can be equipped with position sensors. However, this adds extra hardware cost, which adds up to the large number of stepper motors.

Therefore, advantageously, the quantity representing the rotational speed is detected as the current change after a switching operation of the power output stage. As a rule, means for detecting the current are anyway present in order to set the predetermined setpoint current. The speed influences the induced reverse voltage, which precludes the structure of the current.

The higher the speed, the greater the induced voltage and the lower the current increase. In this respect, the course of the current changes, the speed fluctuations are represented.

In order to adjust the setpoint for the amount of current, the deviation of the current change from reference values can be detected, and the setpoint is adjusted depending on the deviation.

To solve the problem, a cheese-producing textile machine is further proposed with a variety of similar jobs, each having a plurality of individual stepper motors designed to drive handling facilities of the workplace, each stepping motor is associated with a power output stage, by means of which a target value for the amount of current is set. According to the invention stepper motors of several workstations for supplying electrical energy to a power supply with limited power are connected, and there are means for detecting a speed fluctuations representing size of at least the stepper motors of a handling device of the plurality of jobs available. Furthermore, control means for adapting the setpoint value for the amount of current of these stepping motors as a function of the variable representing the speed fluctuations are present and thus designed to limit the power absorbed by the power supply.

The control means of the textile machine according to the invention must, in comparison to the prior art, according to which fixed setpoints are specified, although processors are used with a higher computing power, but it can be used power supplies of lower nominal power. This more than compensates for the overhead described above.

According to a preferred embodiment of the textile machine according to the invention, a handling device whose stepping motor can be operated with a setpoint value adjusted for the magnitude of the current as a function of the variable representing the rotational speed variations, is designed as a thread switching device for defined laying of the thread running onto the cross-wound bobbin. The Fadenchangiereinrichtung is one of the largest electrical consumers of a cheese-producing textile machine.

According to a further preferred embodiment of the textile machine according to the invention, it is designed as an open-end rotor spinning machine with a spinning device at each workstation and a handling device, the stepper motor is operated with depending on the speed fluctuations representing size adjusted setpoint for the amount of current is formed as a thread withdrawal device , which pulls the spun yarn from the spinning device. The thread withdrawal device is one of the larger electrical consumers. The adjustment of the nominal current of the thread withdrawal device can be carried out alternatively or in addition to the adaptation of the nominal current of a Fadenchangiereinrichtung.

In accordance with a further embodiment of the textile machines according to the invention, control means for adjusting the setpoint value for the amount of the current of a stepping motor are dependent from the speed fluctuations representing size present at each workstation. Theoretically, it would be conceivable to adapt the setpoint values of the amounts of the currents once to the respective stepper motors. In practice, however, this seems less suitable, since the determination of the setpoints can be made only in the fully assembled state and thus only when the machine is started up. The manual setting with the help of an external control means would be quite expensive. In addition, this would in any case provide an interface for the external control means at each workstation. Therefore, it is easier to provide a fixed control means at each workstation. Then the adjustment of the setpoint values can take place continuously.

The invention will be explained in more detail with reference to an embodiment shown in the drawings.

Fig. 1

eine erfindungsgemäße Kreuzspulen herstellende Textilmaschine mit einer Vielzahl von gleichartigen Arbeitsstellen;

Fig. 2

eine Arbeitstelle einer erfindungsgemäßen Textilmaschine mit mehreren als Schrittmotoren ausgebildete Einzelantrieben zum Antreiben von Handhabungseinrichtungen der Arbeitsstellen;

Fig. 3

eine Leistungsendstufe für eine Phase eines Schrittmotors;

Fig. 4

den Verlauf des Stromes und der Spannung für eine Phase eines Schrittmotors.

Show it:

Fig. 1

an inventive cheese producing textile machine with a variety of similar jobs;

Fig. 2

a workstation of a textile machine according to the invention with a plurality of individual drives designed as stepper motors for driving handling devices of the work stations;

Fig. 3

a power output stage for a phase of a stepper motor;

Fig. 4

the course of the current and the voltage for a phase of a stepping motor.

Fig. 1 shows an open-end rotor spinning machine 11 with a plurality of workstations 1. At each workstation 1, a sliver 14 provided in a sliver can 15 is fed to an open-end spinning device 2. From the spinning device 2, a spun yarn 9 is withdrawn and wound onto a cross-wound bobbin 8. The individual work stations 1 each have a workstation computer 25, which controls the individually motor-driven handling devices of the workstation 1 and is connected via a bus system 13 to a central control unit 12.

For supplying electrical energy, the rotor spinning machine 11 is connected to a power supply network 32. The power grid generally provides a three-phase AC voltage. The magnitude and frequency of this voltage will depend on the particular country in which the rotor spinning machine is used. About the power cord 33, the power supply 31 is supplied by the network 32 with electrical energy. The power supply 31 converts the mains voltage into a voltage suitable for the handling devices. In the present case, this is a DC voltage of 36V. About the power supply line 34, the DC voltage to the consumers of the jobs 1 is provided. In the illustrated embodiment, all workstations as well as all consumers of the workstations are supplied by the same power supply unit 31. However, it is also possible that multiple power supplies are used. This can be summarized jobs, the consumers are each supplied by a power supply. This may be useful, for example, to minimize the length of the power supply lines 34 and thus to reduce the line losses. The lower supply voltage of the workstations compared to the mains voltage leads to an increased power loss. Also are multiple power supplies of lower power often cost less than a power supply larger rated power. It is also possible that only certain consumers of the workplaces are supplied by the same power supply, because a different supply voltage is required for different consumers.

The Fig. 2 shows a perspective shown job 1 and their various handling facilities. Such jobs 1 have, as known and therefore shown only schematically, inter alia, an open-end spinning device 2 and a winding device 3. In the area of the so-called thread withdrawal tube 21 of the open-end spinning device 2, a pivotally mounted piecing element 16 is arranged, the one after a Yarn breakage by a suction nozzle 4 from the cheese 8 8 retrieved thread takes over and prepares the thread end for Wiederanspinnen.

Furthermore, a thread withdrawal device 27 is arranged in this area, which takes over both the removal of the spun yarn 9 from the open-end spinning device 2 during the regular spinning operation, as well as the Wiederanspinnen for the return of a prepared thread 9 is responsible in the open-end spinning device. The thread withdrawal device 27 is driven by the stepping motor 59 with the power output stage 59a.

The winding device 3 is, as usual, from a creel 22 for rotatably supporting a cross-wound bobbin 8, driven via a reversible single drive drive drum 23 and also driven via a single drive Fadenchangiereinrichtung 24. The individual drives each have a stepper motor and a power output stage. The stepping motor of the thread traversing device carries the reference numeral 57 and the associated power output stage Reference numeral 57a. The single drive of the drive drum 23 is formed by the stepping motor 56 and the power output stage 56a. Both drives are controlled by the workstation computer 25. A yarn centering device in the form of a pivotally mounted centering plate 17 can also be arranged in front of the thread-changing device 24, which can be folded into the regular yarn-path when required by a drive consisting of the stepping motor 55 and the power unit 55a. Furthermore, the workstation 1 has a suction nozzle 4, which is adjustable by means of a stepping motor 6 between a thread receiving position lying in the region of the winding device 3 and a yarn transfer position lying in the region of the spinning device 2. The stepper motor 6 is associated with the power output stage 6a.

The suction nozzle 4 carries at the rear a thread catching element 7, which has, for example, an S-shaped thread guide edge, a thread catching contour and a switching plate. Finally, at the distance in front of the regular yarn path of the workstation 1, a stationary Fadenleiteinrichtung 5 is still arranged, which has a downwardly open catching contour 10.

Each of the workstations 1 also has a thread monitor 26, a paraffining device 62 and yarn storage devices 60 and 61, respectively. The yarn storage device 61 is designed as a vacuum-pressurized storage nozzle, while the storage device 60 is formed as a mechanical yarn storage. That is, between two stationary Fadenleitorganen an adjustable Fadenleitorgan is arranged, which, acted upon by a stepping motor 58 with a power output stage 58a, is arranged to be movable relative to the yarn path.

The function of the handling devices described is, for example, in the cited above DE 101 39 075 A1 described in more detail, so that is omitted at this point.

In the present embodiment, the stepper motors 6, 55, 56, 57, 58 and 59 each have two phases. The power output stages 6a, 55a, 56a, 57a, 58a and 59a accordingly each have two H-bridges 40, one of which is in Fig. 3 is shown. The supply voltage of the power supply 31 is connected to the connection point 41 of the H-bridge 40. One phase of the stepper motor is connected to the connection points 42a, 42b. The transistors of the H-bridge 40 are driven by the control element 43 via the control lines 48a, 48b. To generate the pulse pattern 50, as in Fig. 4 shown, the control element 43, the setpoint course 51 and the actual values 52 of the current are available. Both courses are also in Fig. 4 shown. In the exemplary embodiment, the desired value course 51 is sinusoidal. The current actual value 52 is determined by measuring the voltage across the measuring resistor 45. The measurement signal is forwarded to the control element 43 via the control line 47. The current setpoint values 51 are made available to the control element 43 via the control line 46.

The generation of the desired value course 51 takes place by means of the control element 44. For this purpose, the control element 44 is likewise provided with the actual currents 52. By means of the control element 44, the current change is evaluated after a switching operation of the power output stage. The switching operations are determined by the pulse pattern 50. The current profile is compared with a reference curve. From this it can be read whether the drive torque and thus the current amplitude correctly on the actually occurring counter-torque are tuned. If this is not the case, the current amplitude of the setpoint course 51 is adjusted. The frequency remains unchanged. This is predetermined by the speed required for the respective handling process. Due to the current amplitude and the frequency, the sinusoidal setpoint curve is uniquely determined.

Claims (7)

1. Method for operating a textile machine producing cross-wound bobbins (11) with a plurality of similar workstations (1), which each comprise a plurality of individual drives in the form of stepping motors (6, 55, 56, 57, 58, 59) for driving handling devices (4, 17, 23, 24, 60, 27) of the workstation (1), wherein to each stepping motor (6, 55, 56, 57, 58, 59) a power output stage (6a, 55a, 56a, 57a, 58a, 59a) is assigned by means of which a reference value is set for the amount of current, wherein stepping motors (6, 55, 56, 57, 58, 59) of a plurality of workstations (1) are supplied by a power supply unit (31) with limited output
   characterised in that
   a variable representing fluctuations in speed of at least the stepping motors (6, 55, 56, 57, 58, 59) of a handling device (4, 17, 23, 24, 60, 27) of the plurality of workstations (1) is determined, the reference value for the amount of current of said stepping motors (6, 55, 56, 57, 58, 59) is adjusted as a function of the variable representing the fluctuations in speed and in this way the output received from the power supply unit (31) is limited, wherein the fluctuations in speed are caused by acceleration and deceleration during the progression of the steps by the frequency of the current of the stepping motors.
2. Method according to claim 1, characterised in that as the variable representing the fluctuations in speed the change in current is determined after a switching operation of the power output stage (6a, 55a, 56a, 57a, 58a, 59a).
3. Method according to claim 2, characterised in that the deviation of the change in current from reference values is determined and is adjusted as a function of the deviation of the reference value for the amount of current.
4. Textile machine (11) producing cross-wound bobbins comprising a plurality of similar workstations (1), which each comprise a plurality of individual drives in the form of stepping motors (6, 55, 56, 57, 58, 59) for driving handling devices (4, 17, 23, 24, 60, 27) of the workstation (1), wherein a power output stage (6a, 55a, 56a, 57a, 58a, 59a) is assigned to each stepping motor (6, 55, 56, 57, 58, 59), by means of which a reference value is set for the amount of current, wherein stepping motors (6, 55, 56, 57, 58, 59) of a plurality of workstations (1) are connected for supplying electrical power to a power supply unit (31) with limited output,
   characterised in that
   means (45, 47) are provided for detecting a variable representing fluctuations in speed of at least the stepping motors (6, 55, 56, 57, 58, 59) of a handling device (4, 17, 23, 24, 60, 27) of the plurality of workstations (1) as well as control means (44) for adjusting the reference value for the amount of current of said stepping motors (6, 55, 56, 57, 58, 59) as a function of the variable representing fluctuations in speed, which are designed for limiting the output received from the power supply unit (31), wherein the fluctuations in speed are caused by acceleration and deceleration during the progression of the steps by the frequency of the current of the stepping motors.
5. Textile machine producing cross-wound bobbins according to claim 4, characterised in that a handling device (24), the stepping motor (57) of which can be operated by a reference value for the amount of current adjusted to the variable representing the fluctuations in speed, is designed as a thread traversing device (24) for defining the placing of thread (9) running onto the cross-wound bobbin (8).
6. Textile machine producing cross-wound bobbins according to either claim 4 or claim 5, characterised in that the textile machine (11) is designed as an open end rotor spinning machine with a spinning device (2) at each workstation (1), and in that a handling device (27), the stepping motor (59) of which can be operated by a reference value for the amount of current adjusted to the variable representing the fluctuations in speed, is designed as a thread take-off device (27) which draws the spun thread (9) from the spinning device (2).
7. Textile machine producing cross-wound bobbins according to any one of claims 4 to 6, characterised in that the control means (44) are provided for adjusting the reference value for the amount of current of a stepping motor as a function of the variable representing the fluctuations in speed at each workstation (1).

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